Rotor blade locks



H. W. WELSH ROTOR BLADE LOCKS Sept. 19, 1961 3 Sheets-Sheet 1 Filed June 11, 1958 Sept. 19, 1961 H. w. wr-:LsH 3,000,614

' Ro'roR BLADE Locxs Filed June 11, 1958 s sheets-sheet 2 INVENTOR. y

A7' TORNE Y Sept. 19, 1961 H. w. WELSH 3,000,614

ROTOR'BLADE LocKs 5 Sheets-Sheet 5 Filed June 11, 1958 QQ/f INVENTOR.

3,000,614 ROTOR BLADE L'OCKS Harvey W. Welsh, Indianapolis, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware A Filed lune 11, 1958, Ser. No. 741,321 10 Claims. (Cl. 253-77) My invention relates to blade locks for rotary .machines, such, for example, as compressors and turbines.

/It is customary in such machines to mount a row of blades on the periphery of a disk or other rotor structure ,by sliding the roots of the blades into dovetail grooves retention of the blade, ease of application and removal.

Some arrangement must be provided to hold,

Haircut" of the lock, light weight, and simplicity of structure leading to manufacturing economies.

The principal objects of the invention are to improve the retention of blades on turbomachine rotors and to provide an improved blade lockV for such machines.

The nature of the invention and the. advantages there- `of will be clear to those skilled in the art from the succeeding detailed description and drawings of the preferred embodiments ofthe invention.

FIGURE l is a fragmentary sectional view of an axial.

flow compressor rotor taken on a plane containing the axis of the rotor, illustrating a first embodiment of the v invention.

FIGURE 2 is a kfragmentary front elevation view of the same taken on the plane indicated by the line 2 2 in FIGURE 1.

FIGURE y3 is a fragmentary sectional View taken on the plane indicated by the line 3 3 in FIGURE l.

FIGURE 4 is an enlarged view of a portion of FIG- URE l.

' FIGURE 5 is a View similar to FIGURE 1 illustrating' a second embodiment of the invention.

FIGURE 6 is a fragmentary front elevation view of vthe same taken on the plane indicated by the line 6 6 in FIGURE 5. v

FIGURE 7 is a fragmentary sectional View, with parts removed, taken on the plane indicated by the line 7 7 in FIGURE 5.

FIGURE 8 is an enlarged view of a portion of FIG- URE 5.

FIGURE 9 is a view similar to FIGURE l illustratingv a third embodiment of the invention.

FIGURE l0 is a fragmentary front elevation view of the same taken on the plane indicated by the line 10-10 in FIGURE 9.

the plane indicated by the line 11-11 in FIGURE 9.

FIGURE 12 is anenlarged View of a portion of FIG- URE 9.

FIGURE 13 is a fragmentary sectional View taken on the plane indicated by the line 13 13 in FIGURE 12.`

y A1,1 has a relatively heavy lim or flange 16 in which are y cut dovetail slots 17 extending across therim ofthe wheel. These slots may be parallel to the axis ormay be inclined or skewed with respect to the axis.

...55 FIGURE ll is a fragmentary sectional View taken on y 34 in the outer member. I 36 whichgstraddles the edge 37 of a notch 38 in the air F ICE 17. The stalk connects the root to the platform and the airfoil extends outwardly from the platform. The platforms of adjacent blades abut to provide the mner boundary of the flow path through the rotor stage. Webs 24 and 26 extend from the forward and rear faces of the root and stalk to the blade platform. An interrupted air baffle flange 27 extends from the rim to close the spaces between the stalks 22. It will be understood that the rotor structure so far described is merely illustrative of one type of rotor structure to which the invention may ybe applied.

Considering now the form of blade lock illustrated 1n FIGURES 1 to 4, the blade locking means locks the blade to the rotor so that it is fixed in position in the blade slot 17." The locking means 30 of FIGURES 1 to 4 comprises an inner member 31 and an outer member 32. The inner member is generally cylindrical and includes a pilot portion or boss 33 which extends into a circular hole The inner member has a slot baille flange 27. This notch is disposed immediately inwardly of the joining line 38 of adjacent blade platforms.V

Openings are provided in the blade platforms to receive the outer member 32. In the form shown in FIGURES l to 4, the complete opening 39 is defined by aligned openings or recesses in the margins of the blade platforms. As will be seen particularly in FIGURE 3, the

opening 39 is non-circular, although the major portion of the opening is circular, since it includes a notch 41 extending from the circular portion of the opening. This opening is large enough to permit the inner member 31 to be inserted through the opening and lodged in the notch in the air baille flange, ifv desired, although the blade may be slid into the slot 17 with the member 31 in place.

The outer locking member 32`comprises a generally cylindrical body portion 42 having a lug 43 extending l.by the broken line in FIGURE 4. To install this memhole 34 in the outerlocking member.

ber, the body 42 and lug 43 are inserted through the opening 39 with the lug passing through notch 41, and the portion-4 33 of the inner locking member entering the The outermeniber is then rotated about its axisguntil the tab 44 is aligned with the notch 41 and the tab is bent down to coincide with the surface of the platform and lie within the notch 41. In this position, the outer face 46 of the lug 43 engages the inner surface of the platform. This lug thus prevents the inner and outer locking members from flying out of the rotor under the effect of centrifugal force. The engagement of the inner locking member with the air bathe flange onthe rotor, the inter-engagement of the two locking members, and the engagement of the outer locking member with the blade platforms prevents any movement of the blade in the slot. The blade lock may be removed by pressing up the bendable tab 44 from lwithin the platform, rotating the outer member land lifting it through the opening 39, thus freeing the blade for removal.

'ently. This ange is therefore identified as 27".

-dicated by the same reference numerals as in'FIGURES 1 to 4 and need not be described again. The bladei'platform 21' and the air bafHe flange 27 are modified from those previously described to accommodate the different blade locking member. The platform 21 is similar to the platform 21 previously described except that the open- ,ing 39 is entirely defined by a single platform rather than by the edges of two adjacent platforms.

Thus, each locking member locks only one blade. The air bae flange 27 has a portion 51 of thicker section lying under each opening'39, and a radial holes 52 is drilled in each thickened section aligned =with the opening 39. The locking member 53 is similar, in general, to the outer locking member 32 of FIGURES 1 to 4 except that it is provided Vwith a pin o-r boss 54 of reduced section which extends into the hole 52. It will be seen that in this form of the invention the inner locking member is dispensed with and the locking member 53 coacts directly with both the air baffle ange and the blade platform. The locking member is inserted in the same manner Aas the member 32 previously described and retained by the deformable tab 44 as previously described. The shoulder 56 on the locking member engages a surface 57 on the air brame ange 27 which is cut below the remainder of the periphery of the flange 27'.

The form of the invention illustrated in FIGURES 5 to 8 is advantageous over that of FIGURES 1 to 4in that the locking means is simpler. n the other hand, a more complicated air baffle ange is required. 'It will be apparent that the locking means of FIGURES 1 to 4 may be employed with a hole 39 -in a single blade platform and that the locking means of FIGURES to 8 may be employed with a hole defined by the margins of two adjacent blade platforms.

The third form of locking means, illustrated inv-FIG- URES 9 to 13, may also employ the same wheel and blade ystructure as previously described, except that the air baffle flange may be dimensioned somewhat differ- A blade having the platformV 21 withtheiopening' 39 within a single blade platform is illustrated. The blade locking means 60 of this form of the invention comprises a generally cylindrical body 61 with two diametricallyfopposed projectlons 62 extending from the inner end of the'body. As will be seen, projections are bounded by at faces and are -so dimensioned that these faces engage the front and rear lfaces' of the air baffle flange 27 in either of two positionsrof rotation of the retaining member fabout a radial axis, these positions being 90 apart as illustrated. Theiopening 39 with the notch 41 may be the vsame as-prevlously described and the body of the retaining' member has a deformable tab`v44 as previously described. f A lug 71 projects radially fromvr the body 61. vThis lug'71 is dimensioned so that it may 'pass through the notch 41 and will lie against the outer margin 72 of the air baifle ange 27" yafter ythe retaining member has been rotated 90. The outer surface 73 of the lug bears against theradially A inner surface of the blade platform in this position.

When-the retaining member has been inserted and' rotated Y90, the tab 44 is bent down into'the notch 41 to hold the retaining memberY against rotation. The lug'73- then caught under the platform prevents the retaining member from moving radiallyV outward, and since the projections 62 straddle the aid bathe-flange and the body ofthe retainer ts `in the opening 39, the blade is restrained against movement in the slot. It will be apparent that the locking member 60 may be applied at the junction of two adjacent blade platforms sirnilarly'to the retaining member 32 of FIGURES 1 to 4.

The detailed description of preferred embodiments of the invention for the purpose of explaining the principles thereof is not toY be regarded as limiting or restricting the invention, since manymodiiications may be made within `the scope of the invention Aby the exercise of sk1ll-rnjthe art.

I claim:

1. A rotor assembly for a turbomachine comprising, in combination, a rotor having a blade receiving slot in the periphery thereof; a blade having a root slidably mounted lin the slot and a platform disposed adjacent the rotor,

the platform having a non-circular opening therein; means on the rotor aligned with the opening adapted to engage a locking means; `and locking means comprising a gen- `erallycylindrical body having an axis and engaging' the said meansV on the rotor, a lug on the body dimensioned to pass through the opening and engageable with the inner surface of the platform, and a deformable tab on 'the body deformable into the opening to restrain the locking means against rotation about its said axis, the lug and tab being relatively angularly displaced about the axis of the body. 2. A rotor assembly as recited in claim`l in which the locking means has a hole therein and the means on the rotor includes a boss entering the hole.

3. A rotor assembly as recited in claim 1 in which the Vlocking means has a boss extending axially of and from the body thereof and the means on the rotor denes a hole receiving the boss.

' 4. `A rotor assembly as recited in claim l in which the Ameans on the rotor is a flange thereon and the locking "the platform' having a' non-circular opening therein, the

opening being of partially circular contour with anotch extending from one side of the opening; means on the rotor aligned with 'the opening adapted to engage a locking member; 4and a locking member comprising a generally cylindrical body having an axis andl engaging the said means on the rotor, a lug on the body dimensioned to pass through the notch and engageable with the inner surface of the platform, and a deformable-tab on the body deformable into the notch to restrain the memberagainst rotation about its said axis, the lug and tab being relatively angularly displaced about the axis of the vrbody.

7. A rotor assembly as recitedin claim 6 in which the locking member has a hole therein and the means von the Vrotorincludes a bo-ss entering the hole.

' 8. A rotor assembly as recited in claim 6l in which the locking member has a boss extending axially of and from the body thereof and the means `on the'rotor defines a hole receiving the boss.

9.I v-A rotor assemblyl as recited in 'claim 6in whichthe means on the rotor is a flange thereon and the locking member includes parts straddlingthe said tiange.

"10. -A roto-r assembly as'recited in claim 6 in which the gaging the blade platform,

References Citedrin thelle of this patent UNITED STATES PATENTS Peupitch Dee. 9, 1952 '2,867,408 Kolb et la1. Ian. 6, 1959 

